"Monads don't compose" just means you should choose a single monad for most of your functions; in Scala that is usually Future, Either, Try, IO or ZIO. There ar

"Monads don't compose" just means you should choose a single monad for most of your functions; in Scala that is usually Future, Either, Try, IO or ZIO. There are conversion methods between the most common monads. Scala monads are fantastic IMO; Either-based programming is simple and eliminates tons of boilerplate. So is Cats, although the learning curve is steep.